October 20, 2009, 8:54 AM CT

Family tree for cattle, other ruminants

Pairing a new approach to prepare ancient DNA with a new scientific technique developed specifically to genotype a cow, an MU animal scientist, along with a team of international researchers, created a very accurate and widespread "family tree" for cows and other ruminants, going back as far as 29 million years. This genetic information could allow researchers to understand the evolution of cattle, ruminants and other animals. This same technique also could be used to verify ancient relatives to humans, help farmers develop healthier and more efficient cattle, and assist researchers who are studying human diseases, as per the research, which is being published in this week's edition of the Proceedings of the National Academy of Sciences (PNAS).

"We studied 678 different animals, representing 61 different species, and using the new Illumina cow 'SNP chip,' or 'snip chip,' we were able to generate some very precise genetic data for which the chip was not designed," said Jerry Taylor, a professor of animal science in the MU College of Agriculture, Food and Natural Resource and main author of the study. "Our SNP chips allow researchers to examine hundreds of thousands of points on an animal's genome simultaneously. When we applied this technique to 48 recognized breeds of cattle, we were able to construct a family tree and infer the history of cattle domestication and breed formation across the globe"......... Posted by: Kelly      Read more         Source

October 20, 2009, 8:48 AM CT

Carbon-offsetting and conservation

Logged rainforests can support as much plant, animal and insect life as virgin forest within 15 years if properly managed, research at the University of Leeds has found.

Because trees in tropical climates soak up large amounts of carbon dioxide, restoring logged forest through planting new trees could also be used in carbon trading, as per Dr David Edwards, from University's Faculty of Biological Sciences.

Dr Edwards is calling for the inclusion of biodiversity-friendly strategies in carbon trading schemes to ensure that carbon off-setting projects support, rather than undermine, rainforest conservation.

Currently, large plantations of one type of tree, such as Eucalpytus, are popular as carbon off-setting or sequestration projects in the tropics because they also provide commercial benefits, but they do not support tropical biodiversity.

But Dr Edwards has shown that managed restoration of logged forest which can also be used for carbon off-setting brings biodiversity virtually back to pre-logging levels within 15 years, much quicker than forest left to regenerate naturally.

"Our research shows that it is possible to have both carbon sequestration and biodiversity benefits within the same scheme," he said.

"This could act as a strong incentive to protect logged forests under threat of deforestation for oil palm and other such crops. Selectively logged rainforests are often vulnerable because they're seen as degraded, but we've shown they can support similar levels of biodiversity to unlogged forests"......... Posted by: Erica      Read more         Source

October 19, 2009, 6:43 AM CT

Time in a bottle

A 21-year Michigan State University experiment that distills the essence of evolution in laboratory flasks not only demonstrates natural selection at work, but could lead to biotechnology and medical research advances, scientists said.

Charles Darwin's seminal Origin of Species first laid out the case for evolution exactly 150 years ago. Now, MSU professor Richard Lenski and his colleagues document the process in their analysis of 40,000 generations of bacteria, published this week in the international science journal Nature

Lenski, Hannah Professor of Microbial Ecology at MSU, started growing cultures of fast-reproducing, single-celled E. coli bacteria in 1988. If a genetic mutation gives a cell an advantage in competition for food, he reasoned, it should dominate the entire culture. While Darwin's theory of natural selection is supported by other studies, it has never before been studied for so a number of cycles and in such detail.

"It's extra nice now to be able to show precisely how selection has changed the genomes of these bacteria, step by step over tens of thousands of generations," Lenski said.

Lenski's team periodically froze bacteria for later study, and technology has since developed to allow complete genetic sequencing. By the 20,000-generation midpoint, scientists discovered 45 mutations among surviving cells. Those mutations, as per Darwin's theory, should have conferred some advantage, and that's exactly what the scientists found......... Posted by: Janet      Read more         Source

October 15, 2009, 7:47 PM CT

Discovery overturns long-held theory about biological clocks

University of Michigan mathematicians and their British colleagues say they have identified the signal that the brain sends to the rest of the body to control biological rhythms, a finding that overturns a long-held theory about our internal clock.

Understanding how the human biological clock works is an essential step toward correcting sleep problems like insomnia and jet lag. New insights about the body's central pacemaker might also, someday, advance efforts to treat diseases influenced by the internal clock, including cancer, Alzheimer's disease and mood disorders, said University of Michigan mathematician Daniel Forger.

"Knowing what the signal is will help us learn how to adjust it, in order to help people," said Forger, an associate professor of mathematics and a member of the U-M's Center for Computational Medicine and Bioinformatics. "We have cracked the code, and the information could have a tremendous impact on all sorts of diseases that are affected by the clock".

The body's main time-keeper resides in a region of the central brain called the suprachiasmatic nuclei, or SCN. For decades, scientists have believed that it is the rate at which SCN cells fire electrical pulses-fast during the day and slow at night-that controls time-keeping throughout the body......... Posted by: Janet      Read more         Source

October 15, 2009, 7:44 PM CT

Being a standout has its benefits

Standing out in a crowd is better than blending in, at least if you're a paper wasp in a colony where fights between nest-mates determine social status.

That's the conclusion of a study by University of Michigan scientists published online this week in the journal Evolution.

"It's good to be different, to wear a nametag advertising your identity," said graduate student Michael Sheehan, who collaborated on the research with evolutionary biologist Elizabeth Tibbetts.

In earlier research, Tibbetts showed that paper wasps (Polistes fuscatus) recognize individuals by variations in their facial markings and that they behave more aggressively toward wasps with unfamiliar faces. Then last year, Sheehan and Tibbetts published a paper in Current Biology demonstrating that these wasps have surprisingly long memories and base their behavior on what they remember of prior social interactions with other wasps.

That's important in a species like P. fuscatus, in which multiple queens establish communal nests and raise offspring cooperatively, but also compete to form a linear dominance hierarchy. Remembering who they've already bested-and been bested by-keeps individuals from wasting energy on repeated aggressive encounters and presumably promotes colony stability by reducing friction......... Posted by: Kelly      Read more         Source

October 15, 2009, 7:41 PM CT

Do 3 meals a day keep fungi away?

The fact that they eat a lot and often may explain why most people and other mammals are protected from the majority of fungal pathogens, as per research from Albert Einstein College of Medicine of Yeshiva University.

The research, reported in the Journal of Infectious Diseases, showed that the elevated body temperature of mammals the familiar 98.6o F or 37o C in people is too high for the vast majority of potential fungal invaders to survive.

"Fungal strains undergo a major loss of ability to grow as we move to mammalian temperatures," said Arturo Casadevall, M.D., Ph.D., chair and professor of microbiology & immunology at Einstein. Dr. Casadevall conducted the study in conjunction with Vincent A. Robert of the Utrecht, Netherlands-based Fungal Biodiversity Center, also known as Centraalbureau voor Schimmelcultures.

"Our study makes the argument that our warm temperatures may have evolved to protect us against fungal diseases," said Dr. Casadevall. "And being warm-blooded and therefore largely resistant to fungal infections may help explain the dominance of mammals after the age of dinosaurs."

There are roughly 1.5 million fungal species. Of these, only a few hundred are pathogenic to mammals. Fungal infections in people are often the result of an impaired immune function. By contrast, an estimated 270,000 fungal species are pathogenic to plants and 50,000 species infect insects. Frogs and other amphibians are prone to fungal pathogens, one of which, chytridiomycosis, is currently raging through frogs worldwide. Fungi are also important in the decomposition of plants......... Posted by: Janet      Read more         Source

October 15, 2009, 5:23 PM CT

Loss of Tumor-Suppressor and DNA-Maintenance Proteins

A study reported in the recent issue of Nature Genetics demonstrates that loss of the tumor-suppressor protein p53, coupled with elimination of the DNA-maintenance protein ATR, severely disrupts tissue maintenance in mice. As a result, tissues deteriorate rapidly, which is generally fatal in these animals. In addition, the study provides supportive evidence for the use of inhibitors of ATR in cancer treatment.

Essentially, says senior author Eric Brown, PhD, Assistant Professor of Cancer Biology at the University of Pennsylvania School of Medicine, the findings highlight the fact that day-to-day maintenance mandatory to keep proliferative tissues like skin and intestines functional is about more than just regeneration, a stem cell-based process that forms the basis of tissue renewal. It's also about housekeeping, the clearing away of damaged cells.

Whereas loss of ATR causes DNA damage, the job of p53 is to monitor cells for such damage and either stimulate the early demise of such cells or prevent their replication, the housekeeping part of the equation. The findings indicate that as messy as things can become in the absence of a DNOne of the majortenance protein like ATR, failing to remove resulting damaged cells by also deleting p53, is worse. "Because the persistence of damaged cells in the absence of p53 prevents appropriate tissue renewal, these and other studies have underscored the importance not only of maintaining competent stem cells, but also of eliminating what gets in the way of regeneration," explains Brown......... Posted by: Janet      Read more         Source

October 14, 2009, 7:14 AM CT

Whale-sized genetic study for southern hemisphere humpbacks

After 15 years of research in the waters of the South Atlantic and Indian Oceans, researchers from the Wildlife Conservation Society, the American Museum of Natural History, and an international coalition of organizations have unveiled the largest genetic study of humpback whale populations ever conducted in the Southern Hemisphere.

By analyzing DNA samples from more than 1,500 whales, scientists can now peer into the population dynamics and relatedness of Southern Hemisphere humpback whales as never before, and help inform management decisions in the sometimes politically charged realm of whale conservation.

The results of the massive analysis appear in PLoS One, an interactive open-access journal for scientific and medical research. Other contributors to the study include: Columbia University; University of Pretoria; Environment Study of Oman; Instituto Baleia Jubarta and PURCS (Brazil); University of Cape Town; Marine and Coastal Management (South Africa); Faculdade de Biocincias; Agence Nationale des Parcs Nationaux (Gabon); Association Megaptera (France); Universit de La Rochelle (France).

"Humpback whales are perhaps the most studied species of great whale in the Northern Hemisphere, but a number of of the interactions among Southern Hemisphere populations are still poorly understood," said Dr. Howard Rosenbaum, Director of the Wildlife Conservation Society's Ocean Giants Program and main author of the study. "This research illustrates the vast potential of genetic analyses to uncover the mysteries of how humpbacks travel and form populations in the southern ocean basins."........ Posted by: Kelly      Read more         Source

October 14, 2009, 7:11 AM CT

Pets With a Microchip

Animals shelter officials housing lost pets that had been implanted with a microchip were able to find the owners in almost three out of four cases in a recently published national study.

As per the research, the return-to-owner rate for cats was 20 times higher and for dogs 2 ½ times higher for microchipped pets than were the rates of return for all stray cats and dogs that had entered the shelters.

"This is the first time there has been good data about the success of shelters finding the owners of pets with microchips," said Linda Lord, main author of the study and an assistant professor of veterinary preventive medicine at Ohio State University.

"We observed that shelters did much better than they thought they did at returning animals with microchips to their owners".

Lord said that though the American public so far has not seemed to embrace the practice, this study suggests that pet owners should give strong consideration to microchipping their companion animals.

She also noted, however, that no animal identification is more effective than a tag on a collar that includes the pet's name and the owner's phone number.

Animal microchips are implanted at veterinary offices or shelters and contain a unique number that is revealed when the pet is scanned by a microchip detector. The number coincides with contact information that owners register with a microchip manufacturer......... Posted by: Kelly      Read more         Source

October 13, 2009, 8:26 AM CT

Conservation biologists setting their targets too low

Conservation biologists are setting their minimum population size targets too low to prevent extinction.

That's as per a newly released study by University of Adelaide and Macquarie University researchers which has shown that populations of endangered species are unlikely to persist in the face of global climate change and habitat loss unless they number around 5000 mature individuals or more.

The findings have been published online in a paper 'Pragmatic population viability targets in a rapidly changing world' in the journal Biological Conservation

"Conservation biologists routinely underestimate or ignore the number of animals or plants mandatory to prevent extinction," says main author Dr Lochran Traill, from the University of Adelaide's Environment Institute.

"Often, they aim to maintain tens or hundreds of individuals, when thousands are actually needed. Our review observed that populations smaller than about 5000 had unacceptably high extinction rates. This suggests that a number of targets for conservation recovery are simply too small to do much good in the long run".

A long-standing idea in species restoration programs is the so-called '50/500' rule. This states that at least 50 adults are mandatory to avoid the damaging effects of inbreeding, and 500 to avoid extinctions due to the inability to evolve to cope with environmental change......... Posted by: Kelly      Read more         Source